And no, he’s never visited the Mima Mounds Natural Area Preserve, and yes, local researchers aren’t buying it as the answer to end all questions.

There have been many scientific and fanciful theories about the mounds, roughly 5- to 8-feet tall and 30- to 40-feet across spread over 20 square miles. The professor is not the first one to bring up gophers.

One theory is that hordes of Ice Age pocket gophers migrated to the area, following a retreating glacier. The packed gravel left behind by the glacier was too hard to tunnel into, so they spent millennia building their mounds above ground.

Researchers estimate that 10 gophers on an acre could move more than 10,000 pounds of dirt a year, and say that the mound spacing is similar to underground gopher nests, and that the cavities filled with silt could be abandoned tunnels.

Other theories include:

Paul Bunyan Theory: The lumberjack and his Irish workers labored to build a wall similar to the Great Wall of China. The workers quit, leaving behind their full wheelbarrows of dirt.

All Shook Up Theory: Earthquakes created the formations. A geologist was building a doghouse in 1980 noticed that his hammering shook loose soil into piles.

Frozen Prairie Theory: The prairie thawed after the last Ice Age and fractured into blocks that melted into mounds.

Green Gardens Theory: Tribal gardeners built mounds on which they planted veggies.

Fish Net Theory: A 19th-century geologist / zoologist suggested the mounds were fish nests built when the area was under water.

Free pass: Mount Baker-Snoqualmie National Forest is waiving fees on Feb. 15 through 17, Presidents Day Weekend; June 7, National Trails Day; June 14, National Get Outdoors Day; Sept. 27, National Public Lands Day; and Nov. 8 to 11, Veterans Day Weekend.

National Parks, including Mount Rainier and Olympic National Park, also offer fee-free days Presidents Day Weekend; National Park Week, April 19 and 20; National Park Service Birthday, Aug. 25; National Public Lands Day, Sept. 27; and Veterans Day, Nov. 11.